Abstract

Anthracnose caused by fungus Colletotrichum gloeosporioides is an important disease of chilli in Asia countries such as Malaysia. This fungus makes the chilli fruits to be unmarketable. In this study, Streptomyces ambofaciens S2 which gave a high antifungal activity was selected and underwent cultural condition optimization. The optimization involved selecting the best carbon and nitrogen sources, seed age, incubation time, pH, percent NaCl (w/v), and fermentation temperature. It was observed that S. ambofaciens S2 gave the highest activity when grown in the present of chitin and peptone as carbon and nitrogen sources, respectively. S. ambofaciens S2 also gave optimal cultural growth and antifungal production at pH 8, incubation temperature of 28°C, 2% of NaCl, 6 days of seed age and 3 days of cultural incubation. By studying the impact of each of the cultural conditions, antifungal activity of S. ambofaciens S2 has been increased to about 30% in comparison with the use of original conditions.

Key words: Streptomyces ambofaciens, anthracnose, chilli, antifungal production, actinobacteria.